Control for telemotors



March 27, 1951 H, g 2,546,462

CONTROL FOR TELEMOTORS Filed Feb. 27, 1947 2 Sheets-Sheet l March 27, 1951 w, l 2,546,462

CONTROL FOR TELEMOTORS Filed Feb. 27, 1947 2 Sheets-Sheet 2 9 AW; MA /76m? Patented Mar. 27, 1951 UNITED 'STATES. PATENT OFFICE CONTROL FOR TELEMOTORS Harry'W. Link, Mel-ion Station, Pa, Application February 27, 1947,'Serial No. 721,195

(Cl. 6054.5l U

10 Claims. 1

My invention relates to remote control apparatus, and more particularly such apparatus wherein a transmitter controls a receiver for responsive movement on either side of a neutral point. The invention is especially useful in connection with telemotors for steering ships, to which use, however, it is not restricted.

One object of the invention is to provide means for positionally synchronizing a transmitter, or control mechanism, and a receiver or operating mechanism, which is governed thereby. A further object is to eiiectthis result without the use of springs or other means which exert diiferent degrees of force in different positions. Other objects and advantages of the invention will be apparent upon consideration of the present specification.

The invention will now be described, by way of illustration, in its application to atelemotor for steering a ship. Thus, in the accompanying drawings- Figure l is an elevation, partly in section and partly in diagrammatic form, showing an apparatus embodying the invention.

Figure 2 is an enlarged elevation of a part of the apparatus shown in Figure l, as viewed from the right therein, certain parts being broken away or shown in vertical section to illustrate the construction of the apparatus.

Figure 3 is an enlarged View taken on line 3-3 Fig. 2.

Figure 4 is an enlarged view of the switch operating finger shown at the top of'Figure l, and viewed as indicated by the arrows 4-4 in Figure 2; and Figure 5 shows the solenoid valve illustrated in Figure l when'in a second position.

In apparatus wherein a control unit governs the action of a remote operating unit, it is important to maintain the two units in synchronized relation. In the past it' has been customary to synchronize such units continually by rather complicated arrangements, or to employ for this purpose opposing mechanical forces such as springs. Such synchronizing apparatus does not always give satisfactory results. I have now found that a control unit and a remove controlled operating unit may be automatically synchronized when in neutral position by means of v a simple and rugged electrical system which is conveniently responsive to the positional relation ships of the transmitter and the receiver when they are not synchronized in their neutral positions.

In the drawings there is shown a control unit 2 comprising a pair of hydraulic cylinders) and I I, wherein plungers I2 and I3, respectively, operate to apply pressure to bodies of liquid contained in the cylinders. The plungers I2 and I3 are'actuated simultaneously in opposite directions from the ships wheel I4 the shaft I5 of which is geared, as by a spur I6 and a gear wheel ll, toa pinion I8 coacting with racks I9 and 20 which are unitary with or fixed to the upper ends of the plungers I2 and I3 respectively.

Thus, by turning the wheel I4 in the clockwise direction (as viewed in Figure 1) the gear wheel'I'I and the pinion I8 are turned counter clockwise, and the plunger I2 is moved downwardly in the cylinder I0, Atthe same time the plunger I3 is moved upwardly in the cylinder I I. correspondingly, by turning the wheel I4 counterclockwise (as viewed. in Figure 1) the gear wheel I! and the pinion l8-* are oppositely turned, and the plunger-I2 is raised, while the plunger [3 is depressed. .j

It is preferred to make all metal parts of the control unit of brass or bronze, in order not to distort the magnetic field in the neighborhood of the ships compass. j

A conduit 2| connects the inner end (the lower end as viewed in Figure 1 of the cylinder II] to a synchronizing valve 22, later tojbe described; A tube 23 extends in continuation of the conduit 2| from the synchronizing valve to an operating unit 24. Similarly a conduit 25 connects the inner end of the cylinder I I to the synchronizing valve 22, and a tube 26 extends in continuation of the conduit 25 from the synchronizing'valve to the operating unit. Thus by moving the plunger I2 downwardly in the cylinder II and simultaneously moving the plunger I3 upwardly in the cylinder II, liquid may be forced from the cylinder In into the operating unit and witha drawnv from the operating unit into the cylinder II. Conversely, by moving the plunger I2 up-i wardly and the plunger I3 downwardly, liquid may be forced from the cylinder I I into the operl ating unit and withdrawn from the operating unit into the cylinder I0.

It is preferred to make the conduits 2| and 25, and the tubes 23 and 2B of seamless steel tubing.

The operating unit 24 is of well-known bale anced construction. It comprises a cylinder block 21, preferably of steel, having a large-diameter bore 28 extending therein from one side and two equal smaller-diameter bores 29, 29 extending therein from the opposite side, the axis of all bores being parallel. A large-diameter ram 30 is fitted for reciprocation in the large diameter bore 28, and a pair of smaller-diameter rams 3|, 3| are similarly fitted in the bores 29, 29, all rams being suitably packed. The rams are fixed externally of the cylinder block 2'! to a rigid frame 32 which is slidably mounted on the cylinder block, all in well-known manner. Thus the rams operate together, the large-diameter ram 38 entering the large-diameter bore 28 as the smallerdiameter rams 3|, 3| are withdrawn from the smaller-diameter bores 29, 23, and vice versa. The large-diameter ram, on the one hand, and

the combined smaller-diameter rams, on the other hand, are designed to have equal displacement, thus balancing the opposing forces in the operating unit.

A connecting rod 33 ties the rigid frame 32 to the steering power control (not shown). Consequently, when the large-diameter ram moves into the cylinder block 21. and the smaller-diameter rams move out of the cylinder block, the connecting rod is moved away from the cylinder block. Opposite movement of the rams draws the connecting rod 33 toward the cylinder block.

The tube 23, extending in continuation of the conduit 2| from the cylinder I0, enters the inner end of the large -diameter bore through a port 34. Correspondingly the tube 26, extending in continuation of the conduit 25 from the cylinder f I, divides and enters the inner end of each smaller-diametercylinder 29 through ports 35, 35.

Consequently, the hydraulic system being filled with liquid and with the synchronizing valve open (as shown in Figure 1), turning the ships wheel M in the clockwise direction will efiect simultaneous movement of the plunger 2 into the cylinder and the plunger |3 out of the cylinder H, which in turn will cause pressure to be exerted within the large-diameter bore 28 and relieved within the smallerdiameter bores 29, 29. The large-diameter ram 30 will therefore move out of the cylinder block 21 and the smaller-diameter rams 3 I, 3| will move into the cylinder block, and the rigid frame 32 will move with the rams to draw th connecting rod 33 toward the cylinder block. Opposite movement of the ships wheel will obviously reverse the movement of the rams and cause the connecting rod to move away from the cylinder block.

The synchronizing valve 22 i of simple and rugged construction. It comprises a closed cylindrical shell 36 and an axially disposed piston rod 31 therein, which extends out of the shell at one end to terminate in a solenoid core 38. Mounted on the piston rod 31 are three pistons, the outer pistons 39 and 40 being equally spaced from the center piston 4|. The outer piston 33, which is nearest the end of the shell through which the piston rod 31 extends, forms an abutment between which and the adjacent end of the shell a spring 42 is compressed. The spring 42 urges the piston rod and pistons toward the opposite end of the shell 36. When the piston rod and pistons are at rest under the action of the spring 42 only, the center piston 4| lies substantially half way between the points at which the conduits 2| and 25 from the control unit are connected into the shell 36. The center piston 4| also lies substantially half way between the points at which the tubes 23 and 26 connecting with the operating unit are connected into the shell. However, such is the design of the synchronizing valve that the distance between the conduit connections is less than the distance between the pistons, whereas the distance between the tube connections is exactly 4 equal to the center-to-center distance between adjacent pistons.

Consequently, with the synchronizing valve 22 in the position illustrated in Figure 1, fiow of liq uid between the cylinder l0 and the bore 28 is through a chamber formed in the shell 36 between the outer abutment piston 39 and the center piston 4|. At the same time flow of liquid between the cylinder II and the bores 29, 29 is through a chamber of substantially equal size formed in the shell 36 between the other outer piston 40 and the center piston 4|. All of the operations so far described are effected with the synchronizing valve in this position.

In order to synchronize the transmitter, or control unit, and the receiver, or operating unit, means is provided for short-circuiting the transmitter and simultaneously locking the receiver in neutral position. Thus, in the embodiment of the invention here particularly described, when the receiver or operating unit 24 returns to neutral position and is out of synchronism with the transmitter or control unit, the synchronizing valve is moved into the position illustrated in Fig. 5. By shutting oil the tubes 23 and 26 the receiver or operating unit is locked in position, since liquid can neither enter nor leave the bores 28 and 29, 29 in the cylinder block 27. At the same time the conduits 2| and 25 are connected through the chamber formed in the shell 36 between the center piston 4| and the outer piston 40. Automatic means is provided for releasing the synchronizing means when said transmitter or control unit has also been brought to neutral position.

Accordingly, certain electric circuits, including mechanically operated switches responsive to moving parts of the apparatus, are connected to a source of direct current indicated by poles 43 and 44. The circuit is connected from the pole 43 to a master switch 45, whence the line connects with a junction point 46.

From the junction point 46 one line connects with a selector switch 41 of the normally-open push button type, thence to a transmitter limit switch 48 also of the normally-open push button type. From the limit switch 43, a wire 49 connects with a receiver limit switch 50. From the receiver limit switch, a wire 5| connects with a solenoid coil 52 which coacts with the solenoid core 33 in which the piston rod 3? of the synchronizing valve terminates. Finally, a wire 53 connects the solenoid coil 52 to the pole 44. With all of the switches in this circuit closed, the solenoid coil 52 will be energized, drawing the core 38 therein against the reaction of the spring 42, and the synchronizing valve will take the position shown in Fig. 5.

A second circuit connects the junction point 46 to a second selector switch 54, which it connects in turn to a second transmitter limit switch 55. Thence a lead 55 completes the circuit to the wire 49. Simultaneous closing of the second selector switch 54, the second transmitter limit switch 55, and the receiver limit switch 50' will energize the solenoid and operate the synchronizing valve 22.

As will be obvious, each circuit contains three switches, all of which must be closed before the synchronizing valve is actuated; and it is to be noted that the receiver or operating unit must be in neutral position before the synchronizing valve can be actuated. Furthermore, all switches are closed by the moving parts of the apparatus.

The contact element of the receiver limit switch 50, is carried by a bell crank lever 51, pivoted as at'58 and having a roller 59 on one arm thereof. The bell crank lever normally is urged by any known or convenient force (here gravity) toward closed-switch position. By this construction, when the receiver or operating unit is in neutral position the roller drops into a depression 60 in the rigid frame 32 of the receiver and the switch is closed. When the receiver-moves out of neutral position, the roller 59 rides up out of the depression 60 and the receiver limit switch remains open until neutral position is again attained.

The push button type transmitter limit switches 48 and 55 have rollers 6! and 62, respectively, pivoted at the outer ends of their operating stems. When the transmitter is in neutral position these rollers are in contact with bevel faces 63 and 64. respectively on the outer ends of the racks l9 and 20. Thus, when either rack is elevated the corresponding roller rides along its bevel face and then along its outer surface, thereby closing the adjacent limit switch and maintaining it in closed position. When the rack moves again to neutral position the limit switch opens.

Special means is provided for closing the selector switches 41 and 54. The shaft 65 of the pinion |3 has mounted thereon, by spring-load for frictional actuation thereby, a finger 66, which extends between the actuating rods of the selector switches 47 and 54. Thus, motionof the shaft 65 in one direction will cause the finger 66 to bear against the actuating rod of one switch and close it. Opposite turning of the shaft will cause the finger to close the other selector switch. Frictional mounting of the finger upon the shaft 55 permits the shaft to over-run the position of the finger in which the latter closes a selector switch and to carry the finger over to close the other selector switch as the shaft returns to neutral position. Proper operation of the apparatus is dependent upon this arrangement.

In operation, the synchronizing action is as follows:

Turning the wheel 14 from neutral position in the clockwise direction (Fig. 1) moves the plunger I2- downwardly and the plunger l3 upwardly, thereby drawing the connecting rod 33 toward the cylinder block 27, all in a manner which has already been explained. As the receiver frame 32 moves out of neutral position the roller 59 rides out of the depression in the frame and the receiver limit switch is opened. At the same time the plunger i3 is raised and the rack 2!! closes the transmitter limit switch 55. The shaft 65, turning counterclockwise as viewed in Figure 1, carries the finger 56 over to close the selector switch and continues to turn beyond the extreme position of the finger. No current now flows in the circuits at this time. If the transmitter and the receiver are synchronized, the racks l9 and 25 will return exactly to neutral position and both transmitter limit switches will be open as the wheel 59 drops into the depression in the rigid frame 32 to close the receiver limit switch 55'. The solenoid 42 will not be energized, and the synchronizing valve 22 willremain open.

v If the transmitter and the receiver are not synchronized, then the receiver will return to neutral position before the transmitter returns to neutral position. The receiver limit switch will therefore be closed While the transmitter limit switch 55 is still held in closed position by the rack 20. Furthermore, because the shaft 55 has 6 over-run-the position of the frictional-ly-m'o'unted finger, the shaft will carry the finger over to close the selector switch 54 before its pinion moves the rack 25 into position to permit the limit switch to open.

Accordingly, the circuit will be closed from the pole 43 through the master switch 45, through the selector switch 54, through the transmitter limit switch 55, the lead 56, the wire 49 through the receiver limit switch 50, the wire 5| of the solenoid coil 52 and the wire 53 to the pole 44. In consequence, the solenoid will move the synchronizing valve 22 into the position shown in Fig. 5. Thus the receiver will be locked in neutral position while the transmitter will be shortcircuited. Further clockwise turning of the wheel -i 4 will bring the transmitter into neutral position. whereupon the transmitter limit switch will open, breaking the circuit. As a result, the solenoid coil 52 will be de-energized and the synchronizing valve will return to its original position.

Similar action results when the wheel is turned in the counterclockwise direction with respect to Fig. 1.

It is to be noted that the synchronizing action is entirely automatic. It is also to be noted that synchronizing action takes place only when returning to neutral position, and that during synchronization (which is substantially instantaneous) the receiver is locked in neutral position. This is particularly advantageous in steering a ship, since the helmsman never loses rudder control.

At times it may be necessary to synchronize the transmitter and receiver when the receiver is not in neutral position. For example, when fueling a ship at sea it is desirable to maintain the rudder at a small angle while the fueling ship and the fuel ship are lashed together and under way, which may be necessary for as long as twenty-four hours. A slight leak or by-passing in the telemotor system may require constant advance of the helm angle, which may dissipate the entire plunger stroke of the transmitter or control unit.

Emergency means for synchronizing the transmitter and the receiver. while the latter is away from neutral position is therefore provided. Thus an emergency switch 61 is provided for locking the receiver in any position while shortcircuiting the transmitter. also provided whereby the transmitter may be set at the locked setting of the receiver.

As will be at once apparent, closing of the emergency switch 6! will short-circuit the solenoid coil from the junction point 46 throughia wire 69, the wire 5| and the wire 53, therebyacmating the synchronizing valve 22 to lock the receiver and short-circuiting ,the' transmitter. Furthermore, theinolicator 68 will show the position of the transmitter, which when short-circuited may be moved to a setting corresponding to that at which the receiver is locked.

The indicator here illustrated comprises a needle 10 pivoted to move over a scale H adjacent the wheel l4. The needle is carried by a stem 12 fixed to a bevel wheel 13 in mesh with a second bevel wheel [4 which is driven through gear segment I5 from the pinion IS. The gearing is such that when the transmitter and receiver are synchronized the needle always indicates the midder angle on the scale.

Accordingly, to synchronize the transmitter and receiver when the latter is not in the neutral position, the emergency switch is closed, thus An indicator 68 is locking the receiver-and short-circuiting the transmitter, and the position of the transmitter is adjusted. until the-indicator indicates that the transmitter is in position corresponding to the locked positon of the receiver. The emergency switch is then opened. The emergency switch is kept open during all normal operations.

Adjacent the wheel shown in Figure 2 is shown a conventional steering connection IE to a flying bridge above the wheel house. A clutch TI is indicated whereby the connection may be used or disconnected.

From the foregoing, it will be apparent that simple, rugged and automatic means have been providedfor synchronizing a transmitter or control unit and a remotely controlled receiver or operating unit. Furthermore, manually actuated synchronization is provided for use in unusual circumstances.

The form of the invention herein described and illustrated in the accompanying drawings is presented merely to indicate how the invention may be employed. Other forms and applications of the invention will suggest themselves to those familiar with remote control apparatus.

I claim:

1. Remote control apparatus comprising a hy draulically operated receiver and a hydraulic transmitter for operating said receiver in combination with synchronizing apparatus for said transmitter and receiver, said synchronizing apparatus comprising means to hydraulically disconnect said transmitter and receiver and-simul taneously to hydraulically lock the latter in a predetermined position, automatic means to D- erate said disconnecting and locking means only when said receiver is in said predetermined position including control means operated by said transmitter, and other control means operated by said receiver only in said predetermined posi-v tion thereof.

2-. Remote control apparatus comprising a hydraulically operated receiver and a hydraulic transmitter for operating said receiver in combination with synchronizing apparatus for said transmitter and receiver, said synchronizing apparatus comprising means to hydraulically disconnect said transmitter and receiver and simultaneously to hydraulically lock the latter in a predetermined position, automatic means to operate said disconnecting and locking means only when said receiver is in said predetermined position including control means operated by said transmitter and control means operated by said receiver only in said predetermined position thereof, and other control means actuated by said transmitter alone for rendering said automatic means ineffective to operate said disconnecting and locking means. I 3. Remote control apparatus comprising a'hy draulic control unit, a hydraulic operating unit actuated by said control unit, means ,for synchronizing the operation of said units comprising a synchronizing valve to hydraulically disconnect said control unit and operating unit and simultaneously to hydraulically lock the latter in av predetermined position, and electrical means automatically actuated by said control unit for operating said synchronizing valve only when said operating unit is in neutral position including control means actuable by said operating unit in said predetermined position only of the latter.

4. Remote control apparatus comprising a hydraulic control unit, a hydraulic operating 1:4 .13 dq il 'p d' m qn rol unit. means for synchronizing the operation of said units QQll'if prising a synchronizing valve to hydraulically disconnect said control unit and operating unit and simultaneously hydraulically lock the lat ter in a predetermined position, electrical means for operating said synchronizing valve only when the operating unit is in said predetermined p051:- tion including control means actuable by said control unit, and other control means actuable .by said operating unit in said predetermined po automatically actuated by said control unit operatively connected to the coil of said solenoidtype valve for operating said valve. 1 j

6. Remote control apparatus for steering a ship comprising a hydraulic control unit operated by the ships wheel, a hydraulic operating unit operatively tied to the steering power control of the ship, and hydraulic connections between said units, in combination with means for synchronizing said units comprising a synchronizing piston valve connected across said hydraulic connections for disconnecting said control unit from said operating unit and simul taneously hydraulically locking said operating unit in a predetermined position, a solenoid hav' ing its core connected to the piston rod of said valve, an electrical circuit operatively connected to the coil of said solenoid, and switches operated by moving parts of said control unit and said operating unit for making and breaking said electrical circuit to operate said solenoid.

7. Remote control apparatus for steering a ship comprising a hydraulic control unit operated by the ships wheel, a hydraulic operating unit operatively tied to the steering power control of the ship, and hydraulic connections between said units, in combination with means for synchronizing said units comprising a synchronizing piston valve connected across said hydraulic connections for disconnecting said control unit from said operating unit and simultaneously hydraulically locking said operating unit in a predetermined position, a solenoid having its core con nected to the piston rod of said valve, an electrical circuit operatively connected to the coil of said solenoid, a switch constructed and ar ranged to be closed by said operating unit. at neutral rudder position, and a switch responsive to a moving part of said control unit for closing said circuit to operate said solenoid.

8. Remote control apparatus for steeringa ship comprising a hydraulic control unit openated by the ships wheel, a hydraulic operating unit operatively tied to the steering power con-,- trol of the ship, and hydraulic connections between said units, in combination with means for synchronizing said units comprising a synchronizing piston valve connected across said hydraulic connections for disconnecting said con. trol unit from said operating unit and simultaneously hydraulically locking said operating unit in a predetermined position, a solenoidhaving its core connected to the piston rod of said valve, an electrical circuit operatively connected to the coil of said solenoid, a switch constructed and arranged to be closed by said operating unit at neutralrudder position, a switch responsive to a moving part of said control unit for closing said circuit to operate said solenoid, and an emergency switch connected in parallel in said circuit for independently energizing said solenoid. to close said valve, substantially as described.

9. Remote control apparatus for steering a ship comprising a hydraulic control unit operated by the ships wheel, a synchronizing valve, a hydraulic operating unit operatively tied to the steering power control of the ship, two conduits connecting said control unit with said synchronizing valve, two tubes connecting said valve with said operating unit, said tube connections being spaced more widely than said conduit connections in said valve, a piston rod in said valve, pistons carried by said piston rod and spaced equally with the spacing of said tubes in said valve, and a spring operatively connected with said piston rod for yieldably maintaining one piston between the two conduit connections in said valve and between the two tube connections in said valve, in combination with a solenoid for moving said piston rod against the action of said spring to close the tube connections with said pistons and to short circuit the conduit connections between said pistons, and an electrical circuit connected to said solenoid for closing'said valve.

10. Remote control apparatus comprising a control unit, an operating unit connected to said control unit for actuation thereby, a synchronizing unit connected between said control unit 10 and said operating unit, a solenoid operatively connected to said synchronizing unit, and an electrical circuit connected in series with said solenoid, in combination with an operating unit limit switch connected in said circuit in series with said solenoid, mechanical means governed by said operating unit for closing said limit switch when said unit is in neutral position, a normallyopen control unit limit switch in said circuit in series with said first-named switch positioned to be closed by an element of said control unit when said unit is out of neutral position, a selector switch in series with said limit switches in said circuit, and a frictionally operated finger for closing said selector switch only when said control unit is returning to neutral position, whereby said synchronizing unit is operated only when said limiting switches and said selector switch are all closed.

HARRY W. LINK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,332,050 MacTaggart Feb. 24, 1920 1,445,261 McLeod Feb. 20, 1923 2,185,277 Stelzer Jan. 2, 1940 2,409,175 Adams Oct. 15, 1946 

